June 30, 2013 Millions of people protest against Morsi's year in power.

July 3, 2013 Morsi removed in military intervention backed by popular support.

One person was reported injured following blasts on Saturday in the Hadeek al Qubba area and a police building in eastern Cairo. The attacks come a day after four explosions targeting police in the capital killed six.

Also on Saturday there were reports live rounds had been fired into the air by police to break up about 1,000 anti-government protesters, Reuters news agency reported.

Tear gas and bird shot were also being used, the agency said.

Opponents of the current army-backed interim government are held demonstrations on Saturday, with some calling for the return of the Islamist former president, Mohamed Morsi, who became the first elected Egyptian president in 2012 but was removed from power last year in a military intervention backed by popular support.

Sources said anti-Muslim Brotherhood crowds gathered in Tahrir square, with more arriving throughout the day, chanting "the people demand the execution of the Brotherhood" and "the people demand the affirmation of the regime."

There were further reports of clashes in Mohandiseen at an anti-government protest as security forces dispersed people coming out of a mosque.

Security forces have blocked off areas of the capital. Tahrir Square, the epicentre of the popular revolt that toppled Mubarak in 2011, was closed on Saturday ahead of commemorations.

Mubarak was forced to step down on February 11, 2011 after 18 days of demonstrations in which an estimated 850 people were killed.

The tensions come a day after four bombs killed six people and injured more than 80 in attacks targeting security forces in the capital.

'Plot to spark chaos'

The first blast, at the police's central security directorate building, killed four people and wounded dozens, and left a crater in the ground. It brought down ceilings and damaged exhibits inside the Museum of Islamic Art.

The second blast outside a metro station killed a security officer. The third attacked a police station, while the fourth outside a cinema killed one person.

Ansar Beit al-Maqdis, an al-Qaeda-inspired group led by bedouin fighters in the Sinai Peninsula, said late on Friday that it carried out the attacks to avenge the deaths of Morsi's supporters since his removal.

At least 1,000 people have been killed and thousands of Islamists have been arrested, while the military-installed authorities branded the Brotherhood a "terrorist" organisation in December following a deadly attack on the police.

Mike Hanna on the Cairo explosions

The interim government and the pro-Morsi National Pro-Legitimacy Alliance condemned the bombings.

However, the interim interior minister, Mohamed Ibrahim, called for demonstrations in support of the government and to counter what he said was an Islamist "plot to spark chaos".

Ibrahim also vowed security forces would respond with "firmness" to any attempt by the "Muslim Brothers to sabotage the ceremonies".